A pharmacokinetic study of a novel protease inhibitor was conducted in the cotton-top tamarin, Saguinus oedipus. Three groups of 2 animals per group were established. Animals in each group received a single dose of the test compound at 0.1, 0.3, or 0.6 mg/kg via oral gavage. Animals were tranquilized with ketamine hydrochloride and blood samples were obtained from each animal at 0, 1, 2, 4, 8, 24, and 48 hours following compound administration for measurement of blood levels of the drug. Animals were monitored during the study by clinical observations, physical examinations, body weight, heart rate, and SpO2 measurements. All blood samples were obtained and no significant clinical abnormalities were identified. A second pharmacokinetic study was subsequently conducted. Two animals received the vehicle, 0.5% methylcellulose, and 4 animals received the test compound at 0.3 mg/kg once daily for three consecutive days via oral gavage. Animals were tranquilized with ketamine hydrochloride and blood samples were obtained from each animal at 0, 24, 48, 52, 72, and 96 hours following compound administration for measurement of blood levels of the drug. Animals were monitored during the study by clinical observations, physical examinations, and body weight measurements. All blood samples were obtained and no significant clinical abnormalities were identified.